Supradiaphragmatic lymphadenopathy is a rare finding in prostate cancer. The occurrence of multiple lymphadenopathies forming a conglomerate that resembles lymphoma is also rarely encountered in prostate cancer diagnosis. We present the case of a 71-year-old man who has experienced bilateral leg swelling in the last four months. Multiple lymphadenopathies were detected in the intra-abdominal and supradiaphragmatic regions, along with several metastatic bone lesions. Histopathological and immunohistochemical evaluations confirmed a diagnosis of prostate adenocarcinoma, not otherwise specified (NOS), with a Gleason score of 4+3=7, classified as grade group III, indicating high-volume metastatic prostate cancer. The patient was treated with docetaxel and anti-androgen therapy. His condition improved after eight cycles of chemotherapy, and his prostate-specific antigen (PSA) levels returned to normal. © 2026 Tehran University of Medical Sciences.